In a common western-style flush toilet, water which is supplied from a water supply source such as a city water service pipe and so on is temporarily reserved in a toilet washing tank such as a low tank and so on, and a western-style toilet body is washed by the water which is reserved in the toilet washing tank. The toilet washing tank is mounted at a rear portion of the western-style toilet body or on a side wall of a toilet room in such a manner that the toilet washing tank is positioned outside the western-style toilet body. Furthermore, the toilet washing tank has a large volume in order to spout a large amount of water into the western-style toilet body at one time for ensuring the discharge of filth from the western-style toilet body. However, in such a common western-style flush toilet, a space is required for mounting the toilet washing tank. Accordingly, recently, from the viewpoint of effectively making use of the space, a tankless western-style flush toilet in which an open/close vale (valve for adjusting a flow amount) is mounted between a water supply source and a western-style flush toilet, and which is capable of directly supplying water that is supplied from the water supply source by opening the open/close valve to the western-style flush toilet has been developed (Japanese Patent Laid-open No. 90723/1991, Japanese Patent Registration No. 2841537).
In this tankless western-style flush toilet, a toilet washing water supply device which washes a western-style toilet body with water that is directly supplied from a water supply source is mounted in the western-style toilet body, and the water is directly supplied to the western-style toilet body by opening an open/close valve which is contained in the toilet washing water supply device. In the toilet washing water supply device, the open/close valve has a water-in port as an inlet port and a water-out port as an outlet port at a housing, and at the same time, a valve mechanism which is able to adjust the divergence between the water-in port and the water-out port. The water-in port is connected to the water supply source to be capable of taking water into the housing, and the water-out port is connected to the western-style toilet body to be capable of spouting water from the housing to the western-style toilet body. Furthermore, the open/close valve has a diaphragm as a valve mechanism between the water-in port and the water-out port, and the diaphragm can be bent flexibly by the operation of an electromagnetic valve which is driven by the on-off operation. Accordingly, in this toilet washing water supply device, the diaphragm is bent flexibly by the operation of the electromagnetic valve, and hence, the divergence of the communication between the water-in port and the water-out port can be adjusted.
Moreover, in the open/close valve of the tankless western-style flush toilet, a rim flow passage such as a rim conduit and the like for supplying water to a rim channel which is mounted at an upper portion of a toilet bowl of the western-style toilet body, and a jet flow passage such as a jet conduit and the like for supplying water to a jet hole which generates a forced siphon effect and which is mounted at a bottom portion of the toilet bowl are formed. Then, the open/close valve carries out the rim water-through operation in which water is supplied to the rim flow passage to wash an inner wall surface of the toilet bowl with water which flows down from the rim channel, and the open/close valve carries out the jet water-through operation in which water is supplied to the jet flow passage to spout the water from the jet hole in the inside of the toilet bowl at high speed, and as a result, a forced siphon effect is generated to discharge filth which is excreted in the toilet bowl. Such a rim flow passage and such a jet flow passage are separate paths which are independent from each other. In the above-mentioned tankless western-style flush toilet, there exists a possibility that a negative pressure is generated at an upstream side of the rim flow passage and the jet flow passage to generate a back flow of filth water after the open/close valve which is in the open condition for supplying water is closed to stop supplying water to the rim channel or the jet hole. Accordingly, in such a tankless western-style flush toilet, a vacuum breaker which is communicated with an air is formed at the rim flow passage and the jet flow passage respectively in order to prevent a back flow of filth water.
In addition, in a forced siphon toilet as a tankless western-style flush toilet, the time for supplying water to the rim flow passage and the jet flow passage is controlled by a flow passage switching device in such a manner that each time doesn't overlap with each other. FIG. 20 shows one example of a forced siphon toilet 1 having such kind of flow passage switching device. In this flow passage switching device, two branch water supply pipes Q and R are connected by way of a constant flow amount valve L at the middle of a main water supply pipe P which is connected to a water supply source, and an open/close valve M, N is mounted in each branch water supply pipe Q, R. At the same time, one branch water supply pipe Q is connected to a rim channel 2, and the other branch water supply pipe R is connected to a jet hole 5 which is mounted at the bottom portion of a toilet bowl 4. In such a conventional flow passage switching device, in order to carry out the washing of the forced siphon toilet 1, at first, only one open/close valve M is opened to supply water from the branch water supply pipe Q to the side of the rim channel 2, thereby washing the toilet bowl 4. Then, the open/close valve M is closed, and the other open/close valve N is opened to spout water from the jet hole 5 to a discharge pipe 3 by way of the branch water supply pipe R. Due to this, the discharge pipe 3 is rapidly filled with water, so a siphon effect is swiftly generated. When water is discharged and the siphon effect is finished, the open/close valve N is closed to stop supplying water to the branch water supply pipe R on the side of the jet hole 5, and at the same time, the open/close valve M is again opened to supply water from the branch water supply pipe Q on the side of the rim channel 2 to the toilet bowl 4, thereby forming sealing water in the forced siphon toilet 1.
In an open/close valve for a flush toilet having a valve mechanism in a housing, a water-in port, a water-out port and a communication passage are formed in the housing. The communication passage communicates the water-in port with the water-out port, and the communication passage can be opened and closed by the valve mechanism. In the open/close valve for a flush toilet, as above-mentioned, when the valve mechanism opens the communication passage, water which is taken from a water supply source by way of the water-in port is spouted to a western-style toilet body by way of the water-out port, and accordingly, it is possible to wash the western-style toilet body. When the washing of the western-style toilet body is finished, the valve mechanism closes the communication passage, and spouting water to the western-style toilet body is finished.
Moreover, normally, a manual handle is mounted on a toilet washing tank in such a manner that the manual handle can be fluctuated. If the user fluctuates the manual handle by the manual operation, a chain which is dragged by the manual handle lifts up a valve which is mounted at the bottom of the toilet washing tank to be the released condition. Due to this, water in the toilet washing tank is supplied to the western-style toilet body, and the western-style toilet body is washed. Accordingly, when the manual handle is fluctuated by the manual operation, the manual handle should be fluctuated against water pressure which acts on the valve. Such an operation requires some physical strength, so the manual handle doesn't have necessarily an excellent operability for a serious patient or an old man whose physical strength is considerably weak. Accordingly, recently, a western-style flush toilet in which an electric motor for driving a manual handle automatically is mounted on a toilet washing tank, and at the same time, a toilet washing switch is mounted on a toilet wall which is apart from a western-style toilet body in such a manner that the toilet washing switch is independent from the manual handle separately has been developed. In this western-style flush toilet, after relieving oneself, if the user who is a part from the western-style toilet body carries out the push operation of the toilet washing switch at the toilet wall, the electric motor is driven to flactuate the manual handle automatically, and the washing of the western-style toilet body is carried out. In this case, the push operation of the toilet washing switch doesn't require much physical strength, so an excellent operability can be exhibited.
Furthermore, in the above tankless western-style flush toilet, at the time of washing a western-style toilet body, it is possible to select a water supply amount depending on whether or not a drainpipe which is connected to a trap of a western-style toilet body is an underfloor discharging construction or a floor discharging construction. Therefore, the time for releasing an open/close valve is maintained in accordance with the discharging construction, and the effective washing of the western-style toilet body can be carried out by an appropriate amount of water supply.